1. Field of the Invention
The present invention generally relates to magneto-optical disc recording and/or reproducing apparatus for writing in and/or reading out an information signal from a rewritable magneto-optical disc and, more particularly, is directed to a lifting mechanism for lifting a supporting arm that supports thereon a magnetic head which generates an external magnetic field to a magneto-optical disc.
2. Description of the Related Art
It is customary that a magnetic head for a rewritable magneto-optical disc (hereinafter simply referred to as an MO disc) is located as close as possible to the MO disc in order to generate a sufficient external magnetic field to the surface of the MO disc when an information signal is recorded on the MO disc. Therefore, when the MO disc is loaded onto and/or ejected from the magneto-optical disc recording and/or reproducing apparatus, the magnetic head must be isolated from the MO disc so that the MO disc is prevented from coming in contact with the magnetic head. A mechanism for lifting an arm that supports the magnetic head is therefore used to isolate the magnetic head from the MO disc. The conventional arm lifting mechanism is generally composed of an arm supporting mechanism and an actuator such as a plunger or the like secured to one portion of the arm supporting mechanism.
Since, however, the arm supporting mechanism has little space to spare, the above arm lifting mechanism cannot be incorporated into the small space substantially from a technical standpoint. Further, the arm supporting mechanism has mounted thereon a relatively heavy actuator because it is coupled to the moving mechanism of an optical pickup device. Therefore, the load is increased and a drive motor suffers from the increased load so that the conventional arm supporting mechanism is not suitable for reducing an amount of electric power. To solve the above problem, it is proposed that the actuator is supported to a stationary member such as a chassis or the like that is not operated in a ganged relation with the arm supporting mechanism. However, an arm itself is operated in a ganged relation with the optical pickup device and the arm is moved in the inner and outer diametrical directions of the MO disc during an information signal is written in and/or read out from the MO disc. There is then the problem such that an undesirable load is applied to the arm by the actuator.